The construction, instrumentation and testing of head-neck models composed of simulated human parts and cadaver skulls will be completed and the data obtained will be analyzed to determine the regions of major stress and displacement and their likelihood of physiological damage. The presently available vertebral body and disk simulators, instrumented with both pressure gages and strain measuring devices, will be supplied with the necessary material for replication of muscles, developed in a separate part of the investigation, and will be surrounded with the necessary fluids and external containment material so as to provide a good replication of the soft tissue. Impacts will be produced to the cadaver (and other model) heads by the employment of pendulum strikers so as to obtain collisions of the order of 4 - 10 millisecond duration and stress levels and excursions in the range known to be dangerous to humans. Similar tests will also be conducted using impulsive leading by sudden arrest of the accelerated system. The data collected from strain and pressure gages as well as from high-speed motion pictures will be analyzed and compared with the predictions of a numerical model based on a non-linear finite-difference computational procedure utilizing a maximum stress criterion as a failure characteristic.